System and method for solar-powered engine thermal management

ABSTRACT

A system and method of engine thermal management. Energy may be received from a solar energy source electrically connected to a vehicle propulsion system. At least some of the energy from the solar energy source may be used to heat a component of the vehicle propulsion system. A control module may provide at least some of the energy from the solar energy source to a heater, for example, to heat a component of the vehicle propulsion system prior to starting the vehicle propulsion system. The heater may heat the vehicle propulsion system to temperatures within a predetermined range associated with optimal efficiency of the vehicle propulsion system.

GOVERNMENT INTEREST STATEMENT

This invention was made in whole or in part with government supportunder grant number DE-EE0003379 awarded by the US Department of Energy.The government may have certain rights in the invention.

FIELD OF THE INVENTION

The present invention is related to methods and systems of efficientengine thermal management to improve fuel economy and engine performanceof, for example, internal combustion, diesel, hybrid and extended rangeelectric vehicles. In particular, the present invention is related toheating an engine coolant system using solar energy.

BACKGROUND

Vehicle propulsion or engine systems operate at optimal efficiency whenthe temperature of the engine system components is within a certainrange. If a vehicle is parked for several hours in a cold environment,engine system components, which may include the engine coolant system,engine block, engine head, and other elements, may cool to temperaturesbelow optimal operating temperature. When the temperature of the enginesystem components falls outside of specific temperature bounds, theengine system performance may be sub-optimal. When operating at asub-optimum performance, a vehicle propulsion system may consume greateramounts of fuel than would be consumed under optimal temperatureconditions. A cold engine system may, for example, expend roughly 33% ofthe fuel energy heating the engine coolant system or other engine systemcomponents. An engine system operating at temperatures outside of agiven temperature range may also expel more exhaust emissions. Commonexhaust emissions expelled include carbon monoxide (CO), unburnedhydrocarbons (UHC), NOx and other particulate emissions that are harmfulto the environment. Keeping engine system components within a certaintemperature range results in better fuel economy and reduced emissions.

A method and system to keep vehicle propulsion system components withina given temperature range is needed.

SUMMARY

In some embodiments, energy may be received from a solar energy sourceelectrically connected to a vehicle propulsion system. At least some ofthe energy from the solar energy source may be used to heat a componentof the vehicle propulsion system. A control module may provide at leastsome of the energy from the solar energy source to a heater, forexample, to heat a component of the vehicle propulsion system prior tostarting the vehicle propulsion system. The heater may heat the vehiclepropulsion system to temperatures within a predetermined rangeassociated with optimal efficiency of the vehicle propulsion system.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features, and advantages thereof, may best beunderstood by reference to the following detailed description when readwith the accompanying drawings in which:

FIG. 1 is a schematic diagram of a vehicle and an engine thermalmanagement method and system according to an embodiment of the presentinvention;

FIG. 2 is a schematic diagram of a solar-powered engine thermalmanagement method and system according to an embodiment of the presentinvention;

FIG. 3 is a chart defining different modes for allocating energy todifferent components in a vehicle according to an embodiment of thepresent invention;

FIG. 4 is a graph of cumulative fuel consumption of an engine systemwith respect to time according to an embodiment of the presentinvention;

FIG. 5 is a graph of coolant temperature of an engine system withrespect to time according to an embodiment of the present invention; and

FIG. 6 is a flowchart of a method according to an embodiment of thepresent invention.

Reference numerals may be repeated among the drawings to indicatecorresponding or analogous elements. Moreover, some of the blocksdepicted in the drawings may be combined into a single function.

DETAILED DESCRIPTION

In the following description, various aspects of the present inventionwill be described. For purposes of explanation, specific configurationsand details are set forth in order to provide a thorough understandingof the present invention. However, it will also be apparent to oneskilled in the art that the present invention may be practiced withoutthe specific details presented herein. Furthermore, well known featuresmay be omitted or simplified in order not to obscure the presentinvention.

Unless specifically stated otherwise, as apparent from the followingdiscussions, it is appreciated that throughout the specificationdiscussions utilizing terms such as “processing,” “computing,”“calculating,” “determining,” or the like, refer to the action and/orprocesses of a computer or computing system, or similar electroniccomputing device, that manipulates and/or transforms data represented asphysical, such as electronic, quantities within the computing system'sregisters and/or memories into other data similarly represented asphysical quantities within the computing system's memories, registers orother such information storage, transmission or display devices.

A vehicle propulsion or engine system may operate at optimal efficiencywhen it or certain propulsion or engine system components are within aspecific range of elevated temperatures. An engine system operating atoptimal efficiency may operate in warm engine calibration and advancedcombustion modes resulting in increased fuel economy and reducedtailpipe emissions. Heating the engine system or its components to thesetemperatures may take time. The time it takes to heat the engine systemmay depend on many factors including the target temperatures for thespecific type of engine system, available energy reserves in thevehicle, ambient temperature, weather conditions, the operational modeof the vehicle, for example, whether the vehicle is parked, stopped,driving, accelerating, etc. For example, it may take up to severalminutes to properly heat an engine system. In one embodiment, the timerequired to heat the vehicle propulsion system components may be reducedby providing heat to the components while the vehicle is idle or parked.

Conventional systems do not provide energy to heat engine systems whenthe vehicle is not operating. The engine system therefore may onlyincrease in temperature once the engine is started (and may not increaseas much when the engine is idling). Accordingly, there may be a timedelay after a vehicle has just been started (and possibly extended eachtime the vehicle idles) during which the engine system has not yetreached optimal temperatures. The engine system may operate withsub-optimal efficiency during these time delays by, for example, burningexcess fuel, operating in cold engine calibration, operating inconventional inefficient combustion modes, and releasing increasedemissions.

According to embodiments of the invention, a vehicle propulsion systemmay use solar power to power (e.g., heat) engine systems. Solar powerenergy (e.g., converted to electricity) may be captured via, forexample, one or more (e.g., a network of) solar power cells mounted onor attached to the vehicle. The one or more solar power cells that mayprovide direct power to heating or engine systems, or power via anintermediate battery to the engine systems (e.g., by directingelectricity to the engine systems). The solar power energy may bemanaged independently (or dependently) of other vehicle energy systems(e.g., the main vehicle battery) and may provide power or energy, forexample, even when the vehicle engine is off. Since the solar powerenergy source does not depend on the main battery, the engine system maybegin to be heated prior to starting the engine, for example, to befully (or partially) pre-heated to optimal temperatures by the time thevehicle ignition is started. The energy to heat a component of thevehicle propulsion system may be stored in an energy storage systemseparately from, and distributed by a control module independently of,energy provided to start the vehicle propulsion system.

In one embodiment, an engine system may be pre-heated prior to startingthe vehicle ignition for a time period which is less than, equal to, orgreater than the time typically used to achieve the system's optimalfunctional temperature. In some embodiments, solar power sources maycause a longer time delay to pre-heat the engine system (e.g., one hour)than by using conventional vehicle energy sources (e.g., two to fourminutes) and therefore a pre-heating process using solar power may bestarted earlier than one with non-solar power to account for the extralength of the time delay. In some embodiments, the heating from thesolar power source may be deployed when the temperature of enginecoolant, block, heads or other portions of the vehicle propulsion systemdrop below a predetermined temperature. The solar power source maytherefore be operated to, and power may be distributed or provided toengine components to, ensure that the coolant, or other enginecomponents, remains within a predetermined temperature range. In oneembodiment, the solar power source provides energy to the engine systemto maintain the engine coolant above 45-50 degrees Celsius (° C.). Otherthresholds may be used.

Fluctuations in available energy from the solar power energy source mayfurther affect the time used to heat the engine system by solar power.For example, on a sunny day, solar power energy sources may provide moreenergy and may take less time to power the engine system than on acloudy day or during nighttime. In some embodiments, to account for suchsolar fluctuations, the solar energy sources may have an energy reserveor battery (e.g., separate from the main vehicle battery). The vehiclesolar energy source may therefore harness solar energy from the sunduring sunlight hours and may store the energy to power the enginesystem components at any time, regardless or currently available solarpower (for example, during daytime as well as during nighttime).

Accordingly, a solar-powered engine system in a vehicle may bepre-heated, for example, to optimal temperatures (e.g., for optimal fueleconomy, transition to warm engine calibration, and combustionefficiency, but other or different benefits may occur), prior tostarting the vehicle engine. Accordingly, the conventional time delayduring which the vehicle burns increased fuel, operates in cold enginecalibration, is inhibited from employing advanced combustion modes, andproduces increased tailpipe emissions may be eliminated or substantiallyreduced. In other embodiments, solar energy pre-heating need not occurprior to starting the vehicle engine.

FIG. 1 is a schematic diagram of a vehicle 100 and an engine thermalmanagement system according to an embodiment of the present invention.Vehicle 100 (e.g. a locomotive device such as an automobile, truck,plane, boat, forklift, hybrid electric vehicle (HEV), extended rangeelectric vehicle (EREV), non-locomotive device such as mining equipment,other engine-equipped machine, etc.) may include a main body 102 andoptionally, an auxiliary power unit (APU) 104. Main body 102 may be astandard vehicle and may provide at least driving capabilities.Auxiliary power unit 104 may include an extension that may be integralto or detachable from main body 102.

Vehicle 100 may include one or more photovoltaic (solar) power source(s)106. Photovoltaic sources 106 may include one or a plurality ofinterconnected individual solar cells, solar laminate film, solar curedglass, surface coatings, and/or other photovoltaic devices. Photovoltaicsources 106 may be mounted on either or both of main body 102 andauxiliary power unit 104. Photovoltaic sources 106 generatingelectricity may be mounted on any surface of vehicle 100 that maypotentially be incident to the sun. For example, photovoltaic sources106 may be mounted on the roof, trunk lid, front hood, bumpers, windowguards, the windows themselves via photovoltaic glass laminate or curedglass, or any combination thereof, or other suitable surfaces.Photovoltaic sources 106 may be positioned at fixed positions ororientations or, using a device for tracking sun position, may be movedor movable, or rotated to a position or orientation to collect themaximal amount of solar power. Various arrangements may provide a totalarea of photovoltaic sources 106 of, for example, from approximately onesquare meter (e.g., mounted only on the roof) to about two to threesquare meters (e.g., mounted on the roof, trunk and hood). Other sizesmay be used. Photovoltaic sources 106 may generate, for example, 200 to400 watts of power for vehicle 100. The maximum amount of energygenerated or power outputted by photovoltaic source 106 may bedetermined based on the amount of solar irradiance incident on a cell orother surface of photovoltaic source 106. The solar irradiance may bemeasured by photovoltaic source 106 or independently using one ofseveral types of stand-alone pyranometers such as thermopile-based,silicon photodiode-based, or other type of measurement device.

Vehicle 100 may include a vehicle propulsion system or engine 108providing mechanical power to move the vehicle and/or components ofvehicle 100 (e.g., a fork lift). Engine 108 may be any hydrocarbon orhybrid hydrocarbon/electric fueled power source, such as an internalcombustion engine, a diesel engine, a gasoline engine, a hydrocarbonportion of hybrid powertrain, electric motor (e.g., an AC electric motoror DC electric motor) or any combination thereof.

In one embodiment, engine 108 may operate in multiple enginecalibrations including a cold engine calibration, a warm enginecalibration, and/or other engine calibrations. Based on the enginecalibration (e.g., warm engine calibration) engine 108 is operating in,a power control module, which may include a controller or processor andmemory, or other device may use a set of engine maps corresponding tothe calibration. The engine maps may be tables, matrices, or other formsof data used to control various engine functions. The power controlmodule may use the engine maps to calculate or determine engine systemparameters. The engine system parameters may include, for example,fuel-to-oxidizer ratio and other engine parameters.

Engine 108 may operate in a cold engine calibration below a certainthreshold temperature required for transition to, for example, warmengine calibration or other engine calibration(s). In one embodiment,the threshold temperature to transfer to warm engine calibration may be45-50° C., and the optimal temperature for warm engine calibration maybe 90° C. Other thresholds may be used. Engine 108 may operate atoptimal efficiency in warm calibration by burning less fuel andproducing fewer emissions. By producing fewer emissions, the need forafter-treatment devices may be reduced.

In one embodiment, engine 108 may operate in multiple combustion modesincluding a baseline conventional combustion mode (e.g., directinjection), a stratified or advanced combustion mode, and/or othercombustion modes. An engine operating in baseline conventionalcombustion mode may produce more emissions and higher exhaust gastemperature, which heats up the coolant faster. An advanced combustionmode may be a homogeneous charge compression ignition (HCCI) mode. TheHCCI combustion mode is advantageous because it emits low engineemissions while operating at high efficiency. The HCCI combustion modeemploys functional characteristics of both gasoline and diesel engines.Similar to a gasoline or homogeneous charge spark ignition engine, fuel(e.g., gasoline) and oxidizer (e.g., air or other gases) may becombined. A spark-plug however may not be used to ignite thefuel/oxidizer mixture. Similar to gasoline engines, the emissions fromHCCI combustion may be treated, or cleaned, using, for example, athree-way catalytic converter after-treatment device or other device(s)or method(s). Similar to a diesel engine, combustion of the fuel andoxidizer mixture may occur when the density and temperature of themixture are raised to a certain level. Engine 108 when operating in anHCCI combustion mode may be difficult to control because combustion mayoccur in multiple locations within the cylinder when the fuel andoxidizer mixture reaches a certain temperature and pressure threshold.In order to more precisely control the combustion location and frictionin engine 108, the temperature of engine 108 components must bemaintained within a certain range. Engine 108 may therefore only operateefficiently in HCCI combustion mode when above a minimum temperature. Assuch, an engine 108 with HCCI functionality may operate in aconventional combustion mode when engine components are below a certaintemperature. Engine 108 may then switch or transfer to an advancedcombustion mode (e.g., HCCI) when the engine components, for example,the coolant, reach the threshold temperature. In one embodiment, thethreshold temperature to switch to HCCI combustion mode may be 45-50° C.and the optimal temperature for HCCI combustion may be 90° C. Otherthresholds may be used.

In one embodiment, engine 108 may operate in multiple combustion modesincluding a lean spark ignition direct injection (SIDI) combustion modeand other combustion modes. The benefits of lean SIDI combustion incomparison with conventional fuel injection based combustion modesinclude lower emissions and increased fuel economy. In a lean SIDIcombustion mode highly pressurized fuel is injected into the combustionchamber where it mixes with oxidizer (e.g., oxygen or air). The fuel andoxidizer mix may then be ignited by a spark-plug. The fuel in an SIDIcombustion system is injected at a much higher pressure than in astandard fuel injection system because the ratio of oxidizer to fuel ismuch higher in lean SIDI combustion than in baseline conventionalcombustion modes. The fuel in an SIDI combustion system, for example, isinjected at 100-500 bar pressure or other pressure ranges. In order toraise the fuel to a higher pressure and minimize friction in engine 108,the engine components must be above a threshold temperature. In oneembodiment, the threshold temperature to switch to lean SIDI combustionmode may be 45-50° C. and the optimal temperature for lean SIDIcombustion may be 90° C. Other thresholds may be used.

In one embodiment, engine 108 may operate in multiple combustion modesincluding a premixed charge compression ignition (PCCI) combustion modeand other combustion modes. Similar to HCCI and lean SIDI combustionmodes, the threshold temperature to switch from a conventionalcombustion mode to PCCI combustion mode may be 45-50° C. The optimaltemperature for the PCCI combustion mode may be 90° C. Other thresholdsmay be used.

Vehicle 100 may include one or more energy storage system(s) (ESS) orbatteries 110 and/or 112 for storing energy in main body 102 and/orauxiliary power unit 104. Battery 110 may include one or morelow-voltage (e.g., 12 volt) batteries and battery 112 may include one ormore high-voltage (e.g., 300 volts or greater) batteries. In someembodiments, low-voltage battery 110 may be used for relativelylow-power tasks, for example, operating windshield wiper motors, powerseats, or power door locks, powering a starter for an internalcombustion engine, powering an after-treatment system 114, and/orheating an engine system 108. In some embodiments, high-voltage battery112 may be used for either or both low or high-power tasks, wherehigh-power tasks may include, for example, heating the engine system108, including the coolant, engine head and engine block, powering thetraction motors (if included) of vehicle 100 and propelling vehicle 100.

Photovoltaic sources 106 may be electrically connected to charge orstore energy (e.g., electricity) generated thereby in either or both oflow-voltage and/or high-voltage batteries 110, 112. Low-voltage battery110 may be charged over a range of temperatures of from, for example,−20° C. to 50° C. The voltage used to charge low-voltage battery 110 mayexceed the storage voltage of, for example, 12 volts. In one embodiment,the charging voltage of a lead-acid battery over this temperature rangemay be from approximately 13.5 to 16.5 volts. To charge high voltagebattery 112, a plurality of interconnected photovoltaic sources 106 maybe connected to a DC-DC converter to increase the voltage, for example,to about 300 volts. To charge both low and high-voltage batteries 110,112, a step-down DC-DC converter may be used to reduce voltages toadditionally charge low-voltage battery 110. In yet another embodiment,photovoltaic sources 106 may be connected to form at least two separatearrays with one generating power to high-voltage battery 112 athigh-voltage battery-charging voltages and a second generating power tolow-voltage battery 110 at low-voltage battery-charging voltages. Anysuitable configuration of photovoltaic or solar material or cells may beused, for example, in combination with a DC-DC converter to increasecharging voltage or a step-down DC-DC converter to decrease chargingvoltage, to achieve any target charging voltage. In some embodiments,photovoltaic sources 106 may charge low and high-voltage batteries 110,112 equally, or one before the other, for example, only charginglow-voltage battery 110 after high-voltage battery 112 is fully chargedor vice versa.

Vehicle 100 may include an after-treatment (A/T) system 114.After-treatment system 114 may reduce undesirable exhaust emissions forexample including NOx and particulate emissions.

FIG. 2 is a schematic diagram of a solar-powered engine thermalmanagement system 200 according to an embodiment of the presentinvention.

System 200 may include a vehicle 202 (e.g., vehicle 100 of FIG. 1)having a vehicle propulsion or engine system 204. Vehicle 202 mayinclude or have mounted to it photovoltaic (solar) electric powersources 206 (e.g., photovoltaic sources 106 of FIG. 1), such as, anarray of solar energy cells and/or laminate. Vehicle 202 may include oneor more high-voltage batteries 208 (e.g., high-voltage battery 112 ofFIG. 1), one or more low-voltage batteries 210 (e.g., low-voltagebattery 110 of FIG. 1) and/or one or more auxiliary power modules (APM)214. Auxiliary power module 214 may be a step-up or step-down voltageconverter.

A power control module 212 may control the allocation of energy (e.g. inthe form of electricity) from photovoltaic sources 206 to each ofvehicle 202 components (e.g., engine system 204). Power control module212 may use a current measuring element 218 to measure the electricpower output of photovoltaic sources 206 to determine the poweradjustment necessary to charge or power each of vehicle 202 components.Power control module 212 may use DC-DC converters 220, 222 to adjust(e.g., increase or decrease) the voltage output of photovoltaic sources206.

Power control module 212 may transfer energy (e.g. in the form ofelectricity) from photovoltaic sources 206 to high-voltage battery 208(e.g., and/or APM 214) at the correct high-voltage battery chargingvoltage, for example, via DC-DC converter 222 and to low-voltage battery210 at the low-voltage battery charging voltage, for example, via DC-DCconverter 220. Energy may be transferred to batteries 208, 210 and/orAPM 214 independently or, alternatively, first to high-voltage battery208 and/or APM 214 and, upon saturating the storage capacity or reachingan above threshold amount of stored energy, subsequently transferred tolow-voltage battery 210 (or vice versa). Current measuring element 218may be used to measure current or electricity output from thephotovoltaic sources 206 to determine the available electricity fromsolar power for distribution. Power control module 212 may also transferelectric energy (e.g. in the form of electricity) from photovoltaicsources 206 (e.g., either directly or via an intermediate storagecomponent, such as, low-voltage battery 210) to engine system 204components including one or more heater(s) 224 and/or other componentsof engine system 204. The one or more heater(s) 224 and/or othercomponents each may heat a component of the engine system 204 such ascoolant system 226 (which includes coolant 265), coolant 256, engineblock 228, engine cylinders 230, or other engine system component. Powercontrol module 212 may adjust voltage or current output to each of thevehicle propulsion system components according to the component'sspecific system standards (e.g., and according to different modes inFIG. 3), for example, via DC-DC converter 220 and may split output amongengine system components, for example, via pulse-width modulation (PWM)device 232.

Power control module 212 may include a controller or processor 234 andmemory 236. Processor 234 may issue control signals to (or directly)divert energy (e.g. in the form of electricity) to vehicle 202components via one or more switches 238 and 240. In one example, switch238 may distribute energy to after treatment system 254 or aftertreatment blower motor 216 (e.g., in actuated position (L1)), to the oneor more heater(s) 224 (e.g., in actuated position (L2)), or tolow-voltage battery 210 (e.g., in actuated position (L3)). Switch 240may distribute energy from low-voltage battery 210 to after treatmentsystem 254 or after treatment blower motor 216 (e.g., in actuatedposition (S2)) or to one or more heater(s) 224 (e.g., in actuatedposition (S3)). Heater 224 may be a heat exchanger, heating coil,heating device, heater or other device. Heater 224 may be used totransfer heat to coolant 256, coolant system 226, engine block 228,engine cylinders 230, or other engine system 204 components. Otherswitches or arrangements of switches may be used to transfer energybetween any components in vehicle 202. Power control module 212 may bepart of another engine system, such as an engine or vehicle computersystem.

Controller or processor 234 may be, for example, one or more centralprocessing unit(s) (CPU), a chip or any suitable computing orcomputational device. Processor 234 may include multiple processors, andmay include general purpose processors and/or dedicated processors.Processor 234 may execute code or instructions, for example stored inmemory 236 or long term storage 250, to carry out embodiments of thepresent invention.

Memory 236 may be or may include, for example, a Random Access Memory(RAM), a read only memory (ROM), a Dynamic RAM (DRAM), a SynchronousDRAM (SD-RAM), a double data rate (DDR) memory chip, a Flash memory, avolatile memory, a non-volatile memory, a cache memory, a buffer, ashort term memory unit, a long term memory unit, or other suitablememory units or storage units. Memory 236 may be or may include multiplememory units.

Long term storage 250 may be or may include, for example, a hard diskdrive, a floppy disk drive, a Compact Disk (CD) drive, a CD-Recordable(CD-R) drive, and may include multiple or a combination of such units.

Power control module 212 may input information to determine (e.g., atprocessor 234) the appropriate amount of energy to transfer to enginesystem 204 to heat coolant system 226 within the optimal temperaturerange. Information may include data on conditions that affect theoptimal amount of energy, power, or electricity to distribute orallocate to heater 224, coolant 256, coolant system 226, engine block228, engine cylinders 230 and/or other engine system components toachieve the optimal temperature. Information may include, for example,voltage of one or more energy sources (Vb) (e.g., low-voltage battery210), output current of photovoltaic source 206 (Ip), voltage ofphotovoltaic source 206 (Vp), ambient temperature (Ta), cabintemperature (Tc), after-treatment device bed temperature (Tbed), minimumpower to operate power control module 212 (5 Volts), and/or vehicle mode(e.g., parked mode, driving mode) (Veh. Status). Information may includeadditional or different conditions.

Vehicle 202 may include internal devices, such as, an internal computer,processor 234 and memory 236, temperature, voltage and/or currentsensors, and/or switches 238, 240 activated by predefined environmentalconditions, for example, to store, retrieve or generate information,such as, Vb, Ip, Vp, Tc, and min. power. Vehicle 202 may also include acommunication module 242 to communicate with external devices toretrieve or generate information, such as, Ta and Veh. Status. Externaldevices may include a vehicle telemetrics source 244 such as, a globalpositioning system (GPS), a weather service source 246 providinginformation related to weather, terrain, altitude, or otherenvironmental information, and a mobile computing device 248, such as, amobile computer, a smart phone, a tablet computer, a personal digitalassistant (PDA), etc., which may have a wireless network or cellularnetwork connection to retrieve temperature, weather, geographic orenvironmental condition information from external devices or servers.Alternatively, any or all of the information may be obtained by devicesinternal to vehicle 202 or external to vehicle 202.

Power control module 212 may use information to select one or more modesdefining where the energy from photovoltaic sources 206 is transferred.In one example, power control module 212 may transfer energy accordingto modes, for example, as defined in FIG. 3. Power control module 212may provide energy by providing a current at a voltage (to result in acertain power level), which may be predetermined according to thevoltage of the energy source (e.g., high-voltage battery 208, APM 214 orlow-voltage battery 210).

FIG. 3 is a chart defining relationships between a plurality ofdifferent energy modes 304 for allocating energy to different componentsin a vehicle (e.g., vehicle 100 of FIG. 1) and a plurality of conditions300 according to an embodiment of the present invention. When conditionsor combination of conditions in a set of conditions 300 are detected, acontrol module may select a corresponding mode 304 for operation.Conditions 300 may include, for example, vehicle driving status or modes(e.g., if the vehicle is in park (0) or drive (1)), solar power (e.g.,if there is light from the sun (1) or moon (0)), if a measuredtemperature is greater than, less than, or equal to a referencetemperature (Tref), a coolant reference temperature (Tcoolant), andavailable battery voltage (e.g., if the voltage of one or more energysources (Vb) such as low-voltage battery 210 of FIG. 2 is within amaximum, mid, or minimum voltage range). The measured temperature maybe, for example, a cabin temperature (Tc), current temperature of theengine system 204, current coolant temperature (Tcoolant) when thevehicle is operating, etc. The reference temperature (Tref) may be theoptimal temperature (or temperature range) for the engine system 204,coolant system 226, or after-treatment light-off temperature. Thereference temperature (Tref) may also be equal to the difference betweenthe ambient temperature (Ta) and the cabin temperature (Tc)(Tref=Ta−Tc). The coolant reference temperature (Tcoolant) may be theoptimal temperature (or temperature range) for the coolant 256, coolantsystem 226, or other engine system component.

Each one of the plurality of energy modes 304 may correspond to a set ofswitch positions 302 and energy allocations 306. Energy allocations 306may define the amount or percentage of energy (e.g., electricity)generated at a solar energy source to be allocated to differentcomponents of the vehicle. The energy may be distributed directly fromthe solar energy source (e.g., photovoltaic sources 106 of FIG. 1) orvia an intermediate energy storage system (e.g., low-voltage battery 110of FIG. 1). The components in the example in FIG. 3 are blower motor (X)(e.g., after treatment blower motor 216 of FIG. 2), battery (Y) (e.g.,low-voltage battery 210 of FIG. 2), one or more after treatment systemcomponents (e.g., after treatment system 254 of FIG. 2), and one or moreengine system components (e.g., engine system heater 224 of FIG. 2),although other components may be used. Energy modes 304 in the examplein FIG. 3 include “Sleep 1” (e.g., 0% energy allocated to componentsduring drive mode), “Sleep 2” (e.g., 0% energy allocated to componentsduring park mode), “Blower ON 1” (e.g., 100% energy allocated to theblower), “Blower ON 2” (e.g., 80% energy allocated to the blower and 20%energy allocated to the battery), “Blower ON 3” (e.g., 40% energyallocated to the blower, 40% energy allocated to the battery and 20%energy allocated to one or more engine system component(s)), “TrickleCharge” (e.g., 60% energy allocated to the battery), “Bulk Charge”(e.g., 100% energy allocated to the battery), “After-Treatment” (e.g.,100% energy allocated to the after-treatment component(s) or associatedparts), “Engine Thermal Management” (e.g., 100% energy allocated to theengine system component(s) or associated parts, for example, heater,heating exchanger, heating coil or other device to heat the enginecoolant system or other engine system component(s)), “Engine ThermalManagement+After Treatment” (e.g., 50% energy allocated to the enginesystem component(s) or associated parts, such as, heater, heatingexchanger, heating coil, or other device to heat the coolant system orother engine system component(s) and 50% energy allocated toafter-treatment system component(s) or associated parts), although othermodes may be used. A power control module (e.g., power control module212 of FIG. 2) may store these relationships between conditions 300 andthe energy allocations 306 for energy modes 304, for example, in amemory unit (e.g., memory 230 of FIG. 2). Other or different modes maybe used, and controlling systems and allocating power may be donewithout the use of modes.

The power control module may use a pulse-width modulation (PWM) device(e.g., PWM device 232 of FIG. 2) to divide or shunt electric energy fromthe solar energy source in different proportions among each of thedifferent components based on conditions 300, for example, according toenergy allocations 306.

In one embodiment of the present invention, power control module 212 mayuse energy from a low-voltage energy storage system (ESS) 210 (e.g.,low-voltage battery 110 of FIG. 1) to provide relatively low-voltageenergy to one or more heater(s) 224 to achieve optimal temperatures overa relatively longer time delay (e.g., 20-30 minutes). Power controlmodule 212 may also use energy from a high-voltage battery 208 (e.g.,high-voltage battery 112 of FIG. 1) to provide relatively high-voltageenergy to heater 224 to achieve optimal temperatures over a relativelyshorter time delay (e.g., 2-3 minutes).

In some embodiments, power control module 212 may use solar power energyfrom a solar energy source to fully or partially power heater 224. Powercontrol module 212 may retrieve solar energy from photovoltaic (solarenergy) sources 206, for example, stored in low-voltage energy storagesystem 210.

Power control module 212 may be in communication with a vehicletelemetrics source 244 and/or a mobile device 248, such as, a smartphone, to retrieve information to allocate power or generate a scheduleor timeline for pre-heating engine system 204 or its components.

In some embodiments, a user or vehicle (with one or more associatedusers) may have a driving schedule (e.g., expected times when the usertypically drives, such as, before and after work during the user'sweekday commute, before and after meeting times for clubs or sportpractices on the weekends, etc.), for example, stored in vehicletelemetrics source 244 or mobile device 248, or in another unit such asmodule 212. Power control module 212 may use the driving schedule toactivate heater 224 to pre-heat engine system 204 components (e.g.,coolant system 226, engine block 228, etc.) to optimal temperatures bythe times that engine 204 is expected to be started. The user may bealerted that the engine system has begun pre-heating and/or thatpre-heating is complete, for example, via an alert or alarm on theirmobile device 248. The user may verify (or ignore) the prompt toinitiate, continue, or not cancel pre-heating engine system 204 or,conversely, may reject (or ignore) the prompt to stop, cancel or notinitiate pre-heating engine system 204. In another embodiment, a usermay have a control button, for example, a virtual button on mobiledevice 248, a physical button in the vehicle, or a partial turning of anignition key to initiate pre-heating engine system 204.

In some embodiments, power control module 212 may use weatherinformation (e.g., temperature, clouds, time of sunrise/sunset, etc.,provided by vehicle telemetrics source 244 or mobile device 248) todetermine if pre-heating should be done and/or an amount of energy toallocate to pre-heat engine system 204. In some embodiments, if theweather information indicates future temperature fluctuations, powercontrol module 212 may compensate for such weather changes by likewisechanging the energy allocated to heater 224 to maintain enginetemperature within the optimal range. Power control module 212 may alterthe energy allocated to heater 224 prior to the expected future weatherchanges, for example, by an amount of time estimated to take heater 224to achieve the expected temperature compensation. In some embodimentswhere power control module 212 uses energy from photovoltaic sources206, power control module 212 may provide information related to thegeographical location of the vehicle and may receive a sunlight scheduleindicating measures of predicted future sunlight available to thevehicle over time based on the geographical location of the vehicle.Power control module 212 may change the amount of energy fromphotovoltaic sources 206 reserved for engine system 204 based on thesunlight schedule. In one example, if the sunlight schedule predictsclouds or a decrease in the future amount of available sunlight, powercontrol module 212 may reserve an increased or maximum amount of currentsolar energy resources from photovoltaic sources 206 to be stored inlow-voltage energy storage system 210 to compensate for the predictedfuture decrease in sunlight. Conversely, if the sunlight schedulepredicts direct sun or an increase in the future amount of availablesunlight, power control module 212 may reserve relatively less or aminimum amount of solar energy resources for engine system 204 and maydistribute the remaining available energy from photovoltaic sources 206to be used for other functionality.

In some embodiments, power control module 212 may use vehicle drivingmodes or status (e.g., park mode, drive mode, idle mode, start/stopmode, accelerating, decelerating, etc., which for example may beprovided by vehicle telemetrics source 244) to determine an amount ofenergy to allocate to pre-heat engine system 204 or its components. Thedriving modes may be measured by, for example, sensing the engine 204operation or monitoring the gears of the vehicle. The driving modes maybe predicted (e.g., a driving mode to be expected in the future may be apredicted driving mode) using real time traffic information, forexample, provided by vehicle telemetrics source 244 and/or a mobiledevice 248.

In one embodiment, when engine system 204 is in a driving or start/stopmode, the coolant system or another target component may reach anoptimal temperature. The optimal temperature may be, for example, 45-50°C. or 90° C. (other temperature ranges or thresholds may be used). Whenengine system 204 has reached an optimal temperature, power controlmodule 212 may allocate less energy to heater 224 to heat engine system204 or a target component. Power control module 212 may change theamount of energy from photovoltaic sources 206 reserved for enginesystem 204 and alternatively allocate energy from photovoltaic sources206 to other systems including, for example, an after-treatment systemor any other vehicle systems. In some embodiments, power control module212 may be in ongoing communication with one or more temperaturesensor(s) 252 to receive temperature measurements over time. One or moretemperature sensor(s) 252 may be, for example, located in engine system204 and may measure the temperature of engine coolant system 226, engineblock 228, engine cylinders 230, or any system or component. Powercontrol module 212 may modulate energy or power allocations to pre-heatengine system 204 according to temperature measurements from temperaturesensor(s) 252.

In some embodiments, power control module 212 may use a combination offactors, e.g., driving schedule, weather information (e.g., temperatureand/or sunlight schedules), and driving modes, to determine a timeschedule (e.g., pre-heating start times) and/or an energy schedule(e.g., variable amounts of energy allocated over time) to pre-heatengine system 204 to maintain optimal temperatures. Each set of vehicletelematics or factors used to control pre-heating may provide an extradegree of freedom to control engine system 204.

Other numbers, types and configurations of combustion chambers, exhaustvalves, air-fuel ratios, engines, fuels, and engine systems may be used.

FIG. 4 is a graph of cumulative fuel consumption of an engine systemwith respect to time, and shows that faster coolant heating may resultin less fuel consumption. Graph 400 may represent the cumulative fuelconsumption of a vehicle and engine system during multiple identical NewEuropean Driving Cycles (NEDC) with different coolant system heatingrates. Graph segment 402 may represent the vehicle speed over an NEDCdrive cycle. Graph segment 404 may represent the fuel consumption of avehicle, in which the engine coolant heats slowly over the NEDC drivecycle. The engine coolant system in the vehicle represented by graphsegment 404 was not heated by any heater, heat exchanger or otherdevice. In the example shown, the coolant system in the vehiclerepresented by graph segment 404 heated to 90° C. in 814 seconds. Graphsegment 406 may represent the fuel consumption of a vehicle in which thecoolant is heated with a heater (e.g., a heat exchanger, heating coil,heater or other heating device) during the NEDC drive cycle. The coolantsystem in the vehicle represented by graph segment 406 heated to 90° C.in 325 seconds. As shown in graph 400, a vehicle in which the coolant isheated with a heater or other device may consume less fuel. Of course,other vehicles, and other embodiments, may correspond to graphs withdifferent data.

FIG. 5 is a graph of coolant temperature of an engine system withrespect to time according to an embodiment of the present invention.Graph 500 may represent a coolant temperature, and its decline, from 0to 8 hours after a vehicle with heated coolant is turned off. Coolanttemperature 508 may be the temperature of the heated coolant as itdeclines after the engine is turned off, if no action is taken to heatthe coolant. Coolant temperature 502 may be the minimum coolanttemperature necessary to transfer from a typical combustion mode to anadvanced combustion mode (e.g., HCCI combustion, lean SIDI combustion,etc.) or minimum coolant temperature necessary to transfer to warmengine calibration. Coolant temperature 502 may be, for example, 45-50°C. (other temperature values may be used in other embodiments). Coolanttemperature 506 represents, in one example, the coolant systemtemperature when engine is first turned off, after the coolant has beenheated. Heating energy 504 may be the energy required to maintain thevehicle coolant system temperature at or above coolant temperature 502while the vehicle (or the engine) is not operating. Heating energy 504may be, for example, 6 megajoules (MJ) over 8 hours to maintain thecoolant system temperature at or above 45-50° C. Other heating energyvalues and temperature thresholds may be used in other embodiments.Photovoltaic source 106 may, for example, provide 5.76 MJ of energy over8 hours or other amounts of energy. Heat received by photovoltaic source106 may therefore maintain coolant system 226 temperature near 45-50° C.during direct sunlight weather conditions. Photovoltaic source 106 mayprovide more or less energy depending on the type of photovoltaicsource, the size of the photovoltaic source and other factors.

FIG. 6 is a flowchart of a method according to an embodiment of thepresent invention.

In operation 600, energy may be received from a solar energy source(e.g., photovoltaic sources 106 of FIG. 1) electrically connected to avehicle propulsion system (e.g., engine system 108 of FIG. 1). The solarenergy source may be electrically connected to the vehicle propulsionsystem directly or via intermediate components such as a controller,batteries, etc. Electricity may be produced from the photovoltaicsource.

In operation 610, a component of the vehicle propulsion system (e.g.,coolant system 226 of FIG. 2) may be heated using at least some of theenergy from the solar energy source. For example, coolant system may beheated using electricity from photovoltaic sources.

In operation 620, a control module (e.g., power control module 212 ofFIG. 2) may provide an alert, indication or signal when the component ofthe vehicle propulsion system (e.g., coolant system 226) is heatedwithin a predetermined temperature range associated with optimalefficiency. The alert may be issued to a driver, for example, or to asystem controlling the engine, e.g., to change the mode or calibrationof the engine. The alert may indicate that the vehicle propulsion systemis started with optimal efficiency and may indicate when the vehiclepropulsion system transfers to an advanced combustion mode (e.g., HCCI,PCCI, lean SIDI, etc.) or transfers to a different engine calibration(e.g., warm engine calibration). In some embodiments operations 600-620may occur before the engine of the vehicle is turned on.

Other operations or series of operations may be used.

Embodiments of the present invention may include apparatuses forperforming the operations described herein. Such apparatuses may bespecially constructed for the desired purposes, or may comprisecomputers or processors selectively activated or reconfigured by acomputer program stored in the computers. Such computer programs may bestored in a computer-readable or processor-readable storage medium, anytype of disk including floppy disks, optical disks, CD-ROMs,magnetic-optical disks, read-only memories (ROMs), random accessmemories (RAMs) electrically programmable read-only memories (EPROMs),electrically erasable and programmable read only memories (EEPROMs),magnetic or optical cards, or any other type of media suitable forstoring electronic instructions. It will be appreciated that a varietyof programming languages may be used to implement the teachings of theinvention as described herein. Embodiments of the invention may includean article such as a non-transitory computer or processor readablestorage medium, such as for example a memory, a disk drive, or a USBflash memory encoding, including or storing instructions, e.g.,computer-executable instructions, which when executed by a processor orcontroller, cause the processor or controller to carry out methodsdisclosed herein. The instructions may cause the processor or controllerto execute processes that carry out methods disclosed herein.

Features of various embodiments discussed herein may be used with otherembodiments discussed herein. The foregoing description of theembodiments of the invention has been presented for the purposes ofillustration and description. It is not intended to be exhaustive or tolimit the invention to the precise form disclosed. It should beappreciated by persons skilled in the art that many modifications,variations, substitutions, changes, and equivalents are possible inlight of the above teaching. It is, therefore, to be understood that theappended claims are intended to cover all such modifications and changesas fall within the true spirit of the invention.

1. A method comprising: receiving energy from a solar energy source electrically connected to a vehicle propulsion system; and heating, using at least some of the energy from the solar energy source, a component of the vehicle propulsion system.
 2. The method of claim 1, wherein the energy to heat the component of the vehicle propulsion system is stored in an energy storage system separately from, and distributed by a control module independently of, energy provided to start the vehicle propulsion system.
 3. The method of claim 1, wherein the energy from the solar energy source is used to heat the vehicle propulsion system to temperatures within a predetermined temperature range associated with optimal efficiency for the vehicle propulsion system.
 4. The method of claim 3, comprising initiating heating the vehicle propulsion system prior to starting the vehicle propulsion system.
 5. The method of claim 1, wherein the component of the vehicle propulsion system is engine coolant.
 6. The method of claim 1, comprising receiving an indication of an anticipated start time for starting the vehicle propulsion system and initiating heating the component of the vehicle propulsion system a predetermined amount of time prior to the anticipated start time for starting the vehicle propulsion system.
 7. The method of claim 1, comprising receiving information from a device external to the vehicle and changing the amount of energy from the solar energy source provided to the component of the vehicle propulsion system based on the received information.
 8. A system comprising: a solar energy source to collect solar power; an energy storage system electrically connected to the solar energy source for storing energy generated thereby; and a vehicle propulsion system, wherein the vehicle propulsion system is electrically connected to the energy storage system to receive energy from the solar energy source to heat a component of the vehicle propulsion system.
 9. The system of claim 8, comprising a heater, wherein a controller allocates energy from the solar energy source to power the heater to heat the component of the component of the vehicle propulsion system to temperatures within a predetermined temperature range associated with optimal efficiency for the vehicle propulsion system.
 10. The system of claim 9, comprising a temperature sensor to sense the temperature of the component of the vehicle propulsion system and wherein the control module is to change the amount of energy from the solar energy source allocated to the heater to compensate for the sensed temperature to heat the component to temperatures within the predetermined temperature range.
 11. The system of claim 8, wherein the energy generated by the solar energy source is provided to heat the component of the vehicle propulsion system to temperatures within a predetermined temperature range associated with optimal efficiency for the vehicle propulsion system.
 12. The system of claim 8, comprising a controller to initiate heating the component of the vehicle propulsion system prior to starting the vehicle propulsion system.
 13. The system of claim 8, wherein the component of the vehicle propulsion system is engine coolant.
 14. The system of claim 8, comprising a control module and an external device, wherein the control module receives information from the external device and changes the amount of energy from the solar energy source allocated to the vehicle propulsion system based on the received information.
 15. The system of claim 8, wherein the system is a vehicle.
 16. A method comprising: generating electricity using a solar energy source attached to a vehicle; and heating an engine coolant system of the vehicle using the electricity.
 17. The method of claim 16, wherein the electricity used to heat the engine coolant system is stored in an energy storage system separately from, and distributed by a control module independently of, energy provided to start the engine.
 18. The method of claim 17, comprising initiating heating the engine coolant system prior to starting the engine.
 19. The method of claim 16, wherein the energy from the solar energy source is provided to heat the engine coolant system to temperatures within a predetermined temperature range associated with optimal efficiency for the engine.
 20. The method of claim 16, comprising receiving information from a device external to the vehicle and changing the amount of electricity used to heat the engine coolant system based on the received information. 